It is often desirable to carry cargo as a two-tiered, or double-decked, load. This situation may come about as a result of cargo which is not readily stackable for shipment, or in a mixed load situation, where heavier, awkward loading cargo is carried on the main cargo receptacle deck and lighter or relatively fragile freight is supported on the false deck. Also, cargo often takes the form of individual containers or units which, if not restrained, will shift about within the cargo receptacle. It is well known in the art to use telescoping, adjustable length cargo beams made of either round or rectangular tubing.
U.S Pat. No. 3,836,174. discloses a cargo beam having an elongated center portion of rectangular tubing with the long axis vertically disposed for stiffness, as required for double-decking. One end section is telescopically received within the center portion so as to provide incremental beam length adjustment. A second end section is telescopically fitted into the opposite end of the center section and outwardly biased by a compression spring. Downwardly extending hook members on both ends are inserted through vertical slots in opposite wall mounted tracks and serve to lock the beam in place when installed. The first end hook is engaged by tilting the beam as it is inserted, and locks in place as the beam is leveled. Thus, the second end hook must be inserted with the beam in a level attitude. The second end section includes a locking mechanism, with a spring loaded slide, which includes a tang member extending outwardly from the top of the end section. The slide fills the vertical clearance in the slot above the hook member when extended, so as to lock the second end section in its wall mounted track. The tang member engages an external sleeve, which can be manually displaced to retract the slide and allow withdrawal of the hook member. Removal of the beam requires actuating the sleeve against the slide spring force to retract the slide while, at the same time, overcoming the telescoping spring force to withdraw the end section. The effort involved is significant and a pinched finger is more than possible. There are also potential problems in exposure of the sleeve to being bent and jammed or its movement being blocked by cargo shifting in transit, so that removal is difficult and time consuming. If, however, this external sleeve were to be omitted, as in other known configurations, and the tang is made to extend sufficiently for easy operation, it becomes susceptible to breakage. If it is made short so as to avoid exposure to breakage, it is difficult to operate
Another cargo beam known to be provided in the art is disclosed in U.S. Pat. No. 5,104,269. This beam comprises two opposed end sections telescopically received and outwardly spring loaded within an elongated center portion. Again, the center portion is a rectangular tube with the long axis placed vertically for double-decking strength and stiffness. Each end of the tube receives an end section, which engages a vertical slot in an anchoring track to attach the beam to the opposed cargo receptacle walls. The beam ends include lower hook members which are inserted into the mounting track vertical slots with the beam in a slightly raised position. The beam then drops to bottom in the slot where the hook members keep it from being withdrawn. To be unlocked and removed, an end section must be grasped and pressed inwardly, against the spring load as it is lifted upward. This is not always easily done, particularly when cargo has shifted to press against the beam.
Another known locking beam mechanism, exemplified by U.S. Pat. No. 3,411,459, utilizes an end section with pivotal hook members. Drawings of the disclosed embodiment indicate that the rectangular tubing sections used are oriented with the long axis of the cross-section horizontal, indicating a preference for providing greater section strength and stiffness in that plane, as needed for stabilizing cargo, at the expense of requiring a greater number of braces for double-decking applications. The downwardly extending hook members pivot into a locking position after insertion into closely fitting holes in a horizontal mounting track. A latching member, held in place by gravity related forces, is positioned so as to prevent tilting of the hook members with respect to the track after hooking the end section in place. A tab located at the top surface of the end section is manually displaced to open an access hole and withdraw the latching member, so that a finger can be inserted inside of the end section to disengage the hook member. There is some risk, in cargo stabilizing applications, that the access hole, being on top of the beam, may become covered by shifting cargo and therefore, difficult to access. This of course, is true of any top mounted release mechanism.
No matter the form of the locking mechanism, heavy duty cargo beams made in rectangular tube form for use with anchoring tracks are generally made for installation with the long axis of the rectangle vertical. This is commensurate with the primary strength requirement in the use of such beams being for double-decking. Equal cargo stabilizing stiffness in the horizontal plane is not available without penalty. Obviously, beams could be made with equal stiffness in both planes, but only as a heavier, more expensive and more cumbersome assembly. The simple, lightest weight and least expensive solution of allowing flexibility of choice for orientation of the stiffest axis of the beam is denied by the unavailability of openly accessible release means. While there is a recurring need in the industry for flexibility in double-decking and stabilizing of widely variegated freight, the need is not addressed by presently available freight stabilizing equipment because of weight and competitive price considerations. The thought of installing the presently available rectangular cargo stabilizing beams in other than the conventional, long axis vertical orientation is defeated by potential damage to the latch actuator or lack of access thereto. Thus, there is a continuing need for rugged, easily and safely operated stabilizing equipment. Furthermore, simplicity and low cost are essential considerations.
Objects of the present invention are therefore, first, to provide a cargo stabilizing beam system with the features of light weight and competitive cost necessary to market viability, and secondly to provide an ability for optional beam section orientation according to the cargo stabilizing need, A related object is to provide a beam attachment latch so as to allow positive, protected access for releasing the latch that cannot be blocked by shifting cargo, regardless of orientation, and another object is to provide a beam that is easily and safely operated in any application.
The present invention addresses these objects by providing a rectangular section, adjustable length beam, that operates without axial spring loading. Lower hook members are locked into receiving slots by latches and the latch actuating members are openly accessible through either long side of the rectangular cross-section and, furthermore, do not extend beyond the dimensions of the section. Thus, no matter how the beam is oriented for installation, the actuating member is both accessible and protected from damage. Full utilization of this accessibility is realized by also providing universal anchoring tracks with both horizontal and vertical slots, so that the beam may be installed with the long axis of the section either vertical or horizontal, at the user's option. Inasmuch as the beams of the present invention are adapted to horizontal or vertical installation, an unobvious benefit of the present invention is realized by mounting the universal track itself in vertical sections along the length of the opposed receptacle walls. With such an arrangement, the system achieves even greater flexibility as compared to prior art systems, in that the false deck may be spaced higher or lower for more efficient utilization of the total cubic capacity of the receptacle, while still using the beam to best advantage for supporting or stabilizing purposes. As an added bonus, the anchoring tracks may also be made to include round holes for installation of pre-existing, light duty, round section beam assemblies.